Know how your car alternator works

Thursday September 5 2019

It is advisable to always open your car bonnet

It is advisable to always open your car bonnet and check the alternator to make sure it is functioning well. NET Photo 

By Roland D. Nasasira

Because it is bothersome to remove your battery and charge it externally using hydroelectric power, every car was manufactured with an important part called an alternator.
Hamza Massadda, a mechanic at Wamuco Motors Limited in Industrial Area defines an alternator as a generator or turbine that converts mechanical power into electric power. The converted power is then stored in your car battery to help start the engine. Without an alternator, your battery would have no source of power to ignite or start the engine. An alternator is also sometimes known as an electric motor.
“When the battery is not charging, it means the car electric system will be relying on the alternator and your engine will not start when you turn it off. The battery is meant to start the engine to enable the alternator charge the battery. This is why your car will not start even if you have a full fuel tank. As the car moves after the battery has been fully charged, the surplus power generated by the alternator is used directly by the car electric system via the battery,” Massadda explains, adding, adding that the battery still serves its work to run accessories such as the radio and air conditioner and other accessories.

Position of the alternator
In saloon cars, the alternator is positioned just next to the engine, near the car coolant tank and the radiator. In sport utility vehicles, the alternator is in most cases positioned at the lower side of the engine, making it hard to see.
It is somewhat circular or oval in shape and is protected by a net metallic guard, comprising of interlocked copper wires on the interior.
The alternator is connected to a water pump and the air conditioner pulleys. Musa Kimera, a mechanic at CKK Garage at Wandegeya notes that if the alternator stops working, the power on the battery will eventually get depleted and your car will eventually go off.
Like any other car part, it is advisable to always open your car bonnet and check the alternator to make sure it is functioning well. You as well need to check if the wires that connect the alternator to the engine are not damaged, or lose in anyway.
Sometimes the wires wear out unknowingly or are tampered with when you service your car from different garages with different mechanics.
“The moment one of the three small wires on the alternator socket that transfer mechanical power to the engine is cut or loses its connection from the alternator interior, it will not perform its work of charging the battery,” Kimera explains.

Differences in alternators
Alternator in manual transmission cars do not differ from those with automatic transmission systems. The main difference is in size, which is also dependent on the type or class of the car. For example, an alternator in a Toyota Mark II or any other saloon car is smaller in size compared to the ones in pick-ups, vans or sport utility vehicles, but all of the same shapes.

Alternator service
The alternator comes with an inbuilt motor. Due to dust on the road, when it (dust) gets inside, the motor will function inaccurately. The solution would be to have it opened at a garage to remove the dust using a brush and fit it back. Similarly, during routine service, it may also be accidental when oil or grease drops into the alternator.
In such a scenario, your mechanic also has to open the alternator and have it cleaned thoroughly of oil before it can be fitted back. It is one of the car parts that run without need for oil or greasing.

Low electric supply
If you have to physically support your car windows by pushing them up as the other hand lifts the raising button, it means that the alternator is getting weak and needs replacement. It will also be replaced if car devices such as the radio go off.

Engine stalling
According to Advance Auto Parts, an online portal, if the engine suddenly goes off while driving, it could be an alternator issue. The portal says fuel injection needs a good amount of electrical power, and without it, the engine quickly stalls.

Red battery icon
While driving and a red battery icon appears on your dashboard, it means the alternator is not charging the battery. Sometimes the red battery icon may not show due to the age of the car.


Repair of an alternator
According to Massadda, alternators cannot be repaired, but rather maintained and serviced to keep them in the good road condition. The cost of replacing your alternator is primarily dependent on the type of car. For example, it will cost you approximately Shs500,000 at Wamuco Motors to get a new alternator for saloon cars from Japan, and approximately Shs900,000 for a new one for sport utility vehicles.

Signs of a failing alternator
Isaac Mujjawa, a mechanic in Makindye, observes that you will know that your alternator is failing you if you have to replace your battery in a period shorter than it was meant to serve you. Mechanically, a car battery ought to serve you for between two to five years depending on your driving and user behaviour. This is because a failing alternator will not charge your battery to its full capacity, but rather in instalments, which reduces the battery lifespan.